Variable output three-phase transformer

A three-phase transformer having a primary winding and a secondary winding, the secondary winding comprising:

• a first phase secondary winding having a first predetermined number of turns;
• a second phase secondary winding having a second predetermined number of turns;
• at least two switching means provided on each of said first and second phase secondary windings, there being a first preselected number of turns between said switching means;
• and
• an auxiliary switching means operably connected with said first and second phase secondary windings and having an auxiliary winding to provide an output voltage, said auxiliary winding having a second preselected number of turns equal to the first preselected number of turns between said switching means, wherein the auxiliary switching means is operable between a first position which bypasses the auxiliary winding and a second position which incorporates the auxiliary winding.

In a transformer having a primary winding coupled to a source of electrical power and means for connecting a voltage output to an electrical load, said connecting means comprising:

• a first secondary winding operatively coupled to the primary winding, the first secondary winding having a first plurality of turns and at least two output voltage taps connected to said first secondary winding and spaced thereon a predetermined number of turns such that the first secondary winding has at least a first output voltage level and a second output voltage level;
• first switch means for switching between said voltage output taps;
• a second secondary winding operatively associated with the primary winding, the second secondary winding having a second plurality of turns and at least one output voltage tap connected to said second secondary winding such that the second secondary winding has at least a third output voltage level, wherein said first and third output voltage levels are substantially equal;
• and
• an auxiliary winding having a third predetermined number of turns and a second switch means operably between a first switch position and a second switch position wherein a phase angle of the voltage output is adjusted such that the voltage output level is varied.